Drugs Used In Gastrointestinal Disorders Flashcards
What are some problems of the GI?
Regurgitation, vomiting, diarrhea, weight loss, colic, bloat, flatulence, abnormal stools, and constipation
What are some functions of the GI?
- Intake of fluid and food into the body
- Absorption of nutrients and fluid
- Excretion of waste products
Salivary glands begin enzymatic digestion by producing enzymes that breakdown starch into simpler _____
Carbohydrates
____ delivered to the duodenum break down fats, carbs, proteins and sdoium bicarbonate from the pancreas neutralizes hydrochloric acid from the stomach
Pancreatic enzymes
Where are bile salts produced?
In the liver and delivered in the duodenum aid in the digestion by emulsifying fats
What are the 3 sections of the intestines?
Duodenum where the pancreas is located, the long and highly coiled jejunum, and the short ileum which connects to the large intestines.
Movements of the small intestines mix the intestinal contents called ____ and move them toward the large intestine
Chyme
What is perstalsis?
A wave of contractions that propels contents along the digestive tract
What is sepmentation?
Periodic, repeating pattern of intestinal constrictions that serve to mix and churn the contents
What is the definition of vomiting?
Forceful ejection of the contents of the stomach through the mouth
Vomiting is initiated by the activation of the emetic center in the ____ of the brain.
Medulla
What is the vomiting center connected to?
Nerve pathways to the chemoreceptor trigger zone (CRTZ), the cerebral cortex, and the peripheral receptors in the pharynx, GIT, urinary system, and the heart
Vomiting impulses may be generated by?
Pain, excitement, fear, disturbances in the inner ear, drugs (apomorphine and digoxin), metabolic conditions (wremia, ketonemia, endotoxemia), and irritation of peripheral receptors
What are 2 species that do not vomit?
Horses and rats
What are drugs that induce vomiting called?
Emetics
Emetics are contraindicated when patients are?
Comatose or having a seizure, have depressed pharyngeal reflexes, are in shock or are dyspnic and have ingested strong acid, alkali or other caustic substances
Emetics are classified according to the site of action, what are those 2 sites?
Centrally acting (act on the CRTZ) and Peripherally acting are locally acting and are home remedies or OTC
What centrally acting emetic is a morphine derivative that stimulates dopamine receptors in the CRTZ which then activates the vomiting center?
Apomorphine
True or False
Apomorphine is poorly absorbed after oral administration and is therefore usually administered topically in the conjunctival sac or parenterally
True
What centrally acting emetic is controversial in cats? What is a better solution for cats?
Apomorphine
Xylazine
True or False
Xylazine is a beta 2 agonist
False
Alpha 2 agonist
What locally acting emetic is obtained from plant roots?
Syrup of Ipecac
What does syrup of Ipecac contain?
Alkaloids that irritate gastric mucosa and induce vomiting within 10-30 mins
What locally acting emetic can be used orally? What percent?
Hydrogen Perioxide (3%)
What is the dose for hydrogen perioxide?
1 tsp (5ml) per 5 lbs (not to exceed 45 mls) repeat only once
True or False
Mustard and warm salt water can be used as a locally acting emetic
True
What are antiemetics?
Drugs that are used to prevent or control vomiting
What antiemetic is centrally acting and blocks dopamine and is useful in preventing motion sickness in dogs and cats?
Phenothiazine Derivatives (Chlorpromazine)
What is an example of Phenothiazine Derivatives?
Chlorpromazine
What antiemetic has central and peripheral acting abilities but has a short half life and may often have to be administered as a continuous drip?
Procainamide Derivatives (Metoclopramide)
What is an example of a Procainamide Derivative?
Metoclopramide
What antiemetic can be used for parvo, uremic vomiting, and vomiting associated with chemo?
Procainamide Derivative
True or False
All antihistamines may cause sedation
True
What are some examples of antihistamines?
Dramamine, diphenydramine (benadryl)
What antiemetic if found on the vagal nerve terminals and in the CRTZ cortex?
Serotonin Receptor Antagonists
Which antiemetic works by blocking the binding of substance P (a neurotransmitter involved in vomiting) to NK-1 receptors in the CRTZ?
NK-1 Receptor Antagonists
What is an example of a NK-1 Receptor Antagonist medication?
Maropitant citrate (cerenia)
With H2 Receptor Antagonists one of the primary stimuli for secretion of hydrochloric acid by gastric parietal cells is activation of H2 receptors by ______.
Histamine
True or False
No H2 blockers are OTC products
False
All of them are
What are some examples of H2 Receptor Antagonists that are OTC?
Cimetidine (Tagamet)
Ranitidine (Zantac)
Famootidine (Pepcid)
Which of the H2 Receptor Antagonists is the least potent?
Cimetidine (Tagamet)
Which of the H2 Receptor Antagonists also has prokinetic activity in that it promotes gastric emptying?
Ranitidine (Zantac)
Which of the H2 Receptor Antagonists is the most potent?
Famootidine (Pepcid)
What is an example of a proton pump inhibitor?
Omeprazole (prilosec)
What does proton pump inhibitors bind to?
Binds irreversibly at the secretory surface of the parietal cell to the enzyme Na-K-ATPase
Which enzyme in the proton pump inhibitor is responsible for pumping hydrogen ions into the stomach?
Na-K-ATpase
Which antiulcer medication is used to decrease hydrochloric acid levels in the stomach to aid in the treatment of gastric ulcers , gastritis, esopagitis?
Antacids
True or False
Antacids may also be used in patients with renal failure because antacids bind with intestinal phosphorus and reduce hyperphosphatemia
True
